20 documents found, page 1 of 2
Exploring the Potential of Vine Shoots as a Source of Valuable Extracts and Sta...
Pereira, AR; Carina Costa; Nuno Mateus; Victor de Freitas; Rodrigues, A; Joana OliveiraLarge amounts of vine shoots are generated every year during vine pruning. This residue still presents many of the compounds found in the original plant, including low molecular weight phenolic compounds and structural compounds such as cellulose, hemicellulose, and lignin. For wine-producing regions, the challenge is to develop alternatives that will increase the value of this residue. This work proposes the f...
Bioavailability of anthocyanins and derivatives
Iva Fernandes; Ana Faria; Conceicao Calhau; Victor de Freitas; Nuno MateusAnthocyanins are naturally occurring compounds widespread in plant-derived foodstuffs and therefore abundant in human diet. There are evidences regarding the positive association of their intake with healthy biological effects displayed in vivo. This review aims to highlight some aspects regarding anthocyanins bioavailability; these include a short introductory part of anthocyanin chemistry, stability, occurren...
Flavonoid metabolites transport across a human BBB model
Ana Faria; Manuela Meireles; Iva Fernandes; Celestino Santos Buelga; Susana Gonzalez Manzano; Montserrat Duenas; Victor de Freitas; Nuno MateusThis study aimed to evaluate the transmembrane transport of different flavonoids (flavan-3-ols, anthocyanins and flavonols) and some of their metabolites (methylated and conjugated with glucuronic acid) across hCMEC/D3 cells (a blood-brain barrier (BBB) model). Further metabolism of the tested compounds was assayed and their transport modulated in an attempt to elucidate the mechanisms behind this process. The ...
Analysis of phenolic compounds in cork from Quercus suber L by HPLC-DAD/ESI-MS
Ana Fernandes; Andre Sousa; Nuno Mateus; Miguel Cabral; Victor de FreitasThe aim of the present work was to identify the extractable phenolic compounds present in cork from Quercus suber L The structures of thirty three compounds were tentatively identified by liquid chromatography coupled to electrospray ionisation mass spectrometry (HPLC-DAD/ESI-MS) The majority of those compounds were gallic acid derivatives in the form of either galloyl esters of glucose (gallotannins) combinati...
On the Contribution of Intramolecular Kinetics Properties of an Important Rotam...
Alexandre R F Carvalho; Joana Oliveira; Victor de Freitas; Nuno Mateus; Andre MeloThe kinetics of an important rotamerization occurring in vinylpyranoanthocyanin-phenol pigment (Portisin) was analyzed according to the transition state (TS) formalism. The relevant stationary states, the TS and the equivalent minima, were fully characterized. This included the optimization of the respective geometries and the analytical calculation of all vibrational frequencies. The reaction coordinate was id...
Impact of culture media glucose levels on the intestinal uptake of organic cations
Ana Faria; Rosario Monteiro; Diogo Pestana; Fatima Martel; Victor de Freitas; Nuno Mateus; Conceicao CalhauThere are several data concerning transporters expression and/or regulation in cell lines maintained in different conditions, such as medium glucose concentration. This work aimed to evaluate the influence of two different extracellular glucose concentrations, commonly used in culture media, on the intestinal absorption of organic cations. Thus, the effect of 5.5 mM glucose and 25 mM glucose (HG) in culture med...
Flavonoid transport across RBE4 cells: A blood-brain barrier model
Faria, Ana; Pestana, D; Teixeira, D; Azevedo, J; Victor de Freitas; Nuno Mateus; Conceicao CalhauThere is a growing interest in dietary therapeutic strategies to combat oxidative stress-induced damage to the Central Nervous System (CNS), which is associated with a number of pathophysiological processes, including Alzheimer's and Parkinson's diseases and cerebrovascular diseases. Identifying the mechanisms associated with phenolic neuroprotection has been delayed by the lack of information concerning the ab...
Isolation and Structural Characterization of Anthocyanin-furfuryl Pigments
Andre Sousa; Nuno Mateus; Artur Manuel S Soares Silva; Nicolas Vivas; Marie Francoise Nonier; Isabelle Pianet; Victor de FreitasCondensation reactions of malvidin-3-glucosicle with two representative oak wood furanic aldehydes (furfural and methylfurfural) were conducted in wine-like model solutions. Methylfurfural led to the formation of malvidin-3-glucoside-methylfurfural (603 m/z), whereas furfural led to the formation of malvidin-3-glucoside-furfural (589 m/z). The latter was structurally characterized by 10 and 2D NMR, allowing an ...
Antioxidant properties of anthocyanidins, anthocyanidin-3-glucosides and respec...
Joana Azevedo; Iva Fernandes; Ana Faria; Joana Oliveira; Ana Fernandes; Victor de Freitas; Nuno MateusThe study of the antioxidants properties of three classes of pigments, namely anthocyanidins (cyanidin-Cy, delphinidin-Dp and malvidin-Mv), anthocyanidin-3-glucosides (Cy-3-gluc, Dp-3-gluc and Mv-3-gluc), and portisins (Cy-pt, Dp-pt and Mv-pt) was carried out. The aim was to evaluate the relationship between the structure antioxidant properties of individual anthocyanins and respective derivative pigments. The ...
Understanding the Binding of Procyanidins to Pancreatic Elastase by Experimenta...
Natercia F Bras; Rui Goncalves; Pedro A Fernandes; Nuno Mateus; Maria Joao Ramos; Victor de FreitasHuman diets are rich in secondary metabolites such as polyphenols. These compounds perform a wide range of crucial functions in biological systems and are of great interest for the pharmaceutical and food industries. In this work, the binding mode of the natural polyphenolic compounds from grape seed on the porcine pancreatic elastase surface was studied by experimental and computational methods. Fluorescence q...